Implement "Releases" page

[ghost]

Questions to resolve:

• Will the main page be the current release with a link to "all releases" page, or will the main page directly list all releases?
• Sketch a design or select Tailwind components for each page

Some tasks:

• Implement header
• Adapt Tailwind components or draft html and css
• Define content type for releases database and populate with initial data. One approach would be to use a markdown file for each release and aggregate the front matter for all these files to create a releases list.
• Implement scripts to parse and transform release content from markdown into the desired intermediate format.

[ghost]

We should make some default decisions and design these pages with off the shelf components.

[ghost]

This issue is interrelated with https://github.com/ocaml/ood/issues/18.